Tesla Motors Inc.'s supply agreement with Toyota Motor Corp. for the battery pack in the RAV4 electric vehicle will expire in 2014, putting in question whether Toyota will continue with the lightly-selling utility.

Toyota sells the RAV4 primarily in California with a base price of $49,800. The agreement calls for Toyota buying the powertrains and batteries for about 2,500 RAV4 EVs from Tesla. The 41.8 kilowatt-hour battery pack on...